Effect of ketotifen on Na-glutamine co-transport in intact cells. A, Villus cells. Na-dependent glutamine uptake was determined as a function of 3H-glutamine uptake in the presence of extracellular Na minus uptake in the absence of extracellular Na. Na-dependent glutamine uptake was significantly decreased in villus cells from the chronically inflamed intestine and treatment with ketotifen reversed this inhibition. Ketotifen had no effect on Na-glutamine co-transport in villus cells from the normal intestine. B, Crypt cells. Na-glutamine co-transport uptake was significantly increased in crypt cells during chronic intestinal inflammation and treatment with ketotifen reversed this stimulation. Ketotifen had no effect on Na-glutamine co-transport in crypt cells from the normal intestine.